Apparatus and method having tdmr reader to reader shunts

ABSTRACT

A method of making a magnetic head is provided. The method includes forming a first read sensor and a first electrical contact formed with a first shunt region. The method further includes forming a first mid-shield layer on the first read sensor, the first mid-shield layer being electrically connected to the first electrical contact. Additionally the method also includes forming a second mid-shield layer over the first mid-shield layer. Further, the method also includes forming a second read sensor over the second mid-shield layer, the second read sensor having a second electrical contact formed with a second shunt region electrically connected to the first shunt region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 14/579,785, filed Dec. 22, 2014, the contents of which are incorporated by reference.

BACKGROUND

FIGS. 1A-1B illustrate a related-art two-dimensional magnetic recording (TDMR) transducer 1. Specifically, FIG. 1A illustrates a plan view of the related-art read transducer 1 and FIG. 1B illustrates a schematic view of the related-art two-dimensional read transducer 1. As illustrated, the related-art read transducer may include the two outer shields (15, 50), four mid-shields (20, 25, 55, 60), and three read sensors (80, 85, 90), each having two terminals for a total of six terminals (05, 10, 30, 35, 40, 45). The two outer shields include a first outer shield (S1) 15 and a second outer shields (S2) 50. The four mid-shields include a first mid-shield (MS1) 55, a second mid-shield (MS2) 20, a third mid-shield (MS3) 60, and a fourth mid-shield (MS4) 25.

The three read sensors (illustrated in FIG. 1B) include a first read sensor (R1) 80, a second read sensor (R2) 85, and a third read sensor (R3) 90. The first read sensor (R1) 80 includes a negative terminal (R1−) 05 and a positive terminal (R1+) 45. The second read sensor (R2) 85 also includes a negative terminal (R2−) 10 and a positive terminal (R2+) 35. Further, the third read sensor (R3) 90 includes a negative terminal (R3−) 30 and a positive terminal (R3+) 40.

By employing multiple sensor array designs, TDMR technology may enable multi-terabit density recording. In principle TDMR operation schemes may require the read sensor array structure of the TDMR transducer be longitudinally aligned along the cross track direction with little or no separation to allow different signals to be obtained at the same data track locations simultaneously during read back process. However, a TDMR transducer 1 may suffer a misalignment between adjacent sensor locations and the actual tracks of interests due to skew angle and radius conditions.

Providing smaller vertical separation between adjacent sensors may reduce a skew angle causing misalignment. However, this requires very thin insulating films to separate one reader's mid-shield from the next reader's mid-shield. Such thin insulating films may suffer from Electrical Overstress (EOS) or Electrostatic Discharge (ESD) during manufacturing. The chance of EOS or ESD increases as more read sensors are added between the first outer shield (S1) 15 and a second outer shields (S2) 50. Accordingly, what is needed is a system and method for improving the manufacturing of a magnetic recording read transducer, particular for a TDMR.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A illustrates a plan view of the related-art read transducer 1 and FIG. 1B illustrates a schematic view of the related-art two-dimensional read transducer 1.

FIG. 2 is a schematic view illustrating an exemplary implementation of a disk drive.

FIG. 3 is an ABS view illustrating a portion of a two-dimensional read transducer manufactured from an exemplary implementation of a microstructure of the present application.

FIG. 4 is a plan view of the exemplary implementation of the microstructure of the present application.

FIGS. 5A and 5B are flow charts illustrating an exemplary implementation of a method for manufacturing a magnetic head according to the present application.

DETAILED DESCRIPTION OF THE EXEMPLARY IMPLEMENTATIONS

FIGS. 2-3 depict side and Air Bearing Surface views of a storage drive or disk drive 100. For clarity, FIGS. 3 and 4 are not to scale. For simplicity not all portions of the disk drive 100 are shown. In addition, although the disk drive 100 is depicted in the context of particular components other and/or different components may be used. For example, circuitry used to drive and control various portions of the disk drive 100 is not shown. For simplicity, only single components are shown. However, multiples of one or more of the components and/or their sub-components might be used.

The disk drive 100 includes media 101, a slider 102, a head 103 including a write transducer 104 and a read transducer 110. The media 101 includes tracks 109. The write transducer includes at least a write pole 106 and coil(s) 108 for energizing the pole 106. Additional and/or different components may be included in the disk drive 100. The slider 102, and thus the transducers 104 and 110 are generally attached to a suspension (not shown). The transducers 104 and 110 are fabricated on the slider 102 and include an ABS proximate to the media 101 during use. Although both a write transducer 104 and a read transducer 110 are shown, in other implementations, only a read transducer 110 may be present.

The read transducer 110 includes multiple read sensors 112, 114, and 116. The read sensors 112, 114 and 116 include sensor layers 113, 115 and 117, respectively, that may be free layers (FL) in a magneto resistive junction such as a tunneling magneto resistive (TMR) sensor (such as a current-perpendicular-to-plane (CPP) TMR sensor). As may be apparent to a person of ordinary skill in the art, other types of sensors (such as a giant magneto resistive (GMR) sensor) may also be used. Thus, each sensor 112, 114, and 116 may include a pinning layer, a pinned layer, a nonmagnetic spacer layer, and a free layer 113, 115, and 117, respectively. For simplicity, only the free layers 113, 115 and 117 are separately labeled in FIG. 3. The sensors 112, 114 and 116 may also include seed layer(s) (not shown) and capping layer(s) (not shown). The pinning layer is generally an AFM layer that is magnetically coupled to the pinned layer. In other implementations, however, the pinning layer may be omitted or may use a different pinning mechanism. The free layers 113, 115 and 117 are each shown as a single layer, but may include multiple layers including but not limited to a synthetic antiferromagnetic (SAF) structure. The pinned layer may also be a simple layer or a multilayer. Although shown as extending the same distance from the ABS, the pinned layer may extend further than the corresponding free layer 113, 115, and/or 117, respectively. The nonmagnetic spacer layer may be a conductive layer, a tunneling barrier layer, or other analogous layer. Although depicted as a GMR or TMR sensor, in other implementations, other structures and other sensing mechanisms may be used for the sensor.

The read sensors 112, 114 and 116 are separated by distances d1 and d2 in a down track direction. The down track direction is perpendicular to the cross track direction. The cross track direction and track width direction are the same. In the implementation shown, the distance d1 and d2 between the sensors 112 and 114 and between the sensors 114 and 116, respectively, are the same. However, in other implementations, the distances between the sensors 112, 114 and 116 may not be the same. It may generally be desirable to reduce the distance between the sensors 112, 114 and 116 to reduce the skew effect discussed above. In some implementations, the distances d1 and d2 may each be at least ten nanometers and not more than four hundred nanometers. The read sensors 112, 114 and 116 may have various widths, w1, w2, and w3, respectively, in the track width, or cross-track, direction. In some embodiments, the various widths, w1, w2, and w3 the widths may be substantially equal. However, in other implementations, different widths may be possible. The widths of the sensors 112, 114 and 116 may also be based on the track pitch. The track pitch is the distance from the center of one track to the center of the next track. Further, the widths may depend not only on the track pitch, but also on the distance between the sensors 112, 114 and 116.

The read sensors 112, 114 and 116 may also be displaced along the cross track direction. Therefore, the centers of each of the read sensors 112, 114 and 116 are not aligned along a vertical line that runs the down track direction. In the implementation shown, none of the read sensors 112, 114 and 116 are aligned along a vertical line that runs in the down track direction. In other implementations, some or all of the read sensors 112, 114 and 116 may be aligned. The read sensors 112, 114 and 116 may also partially overlap in the track width/cross track direction. However, in other implementations, the read sensors 112, 114 and 116 may be aligned.

Also shown are bias structures 122, 123 and 124 that magnetically bias the read sensors 112, 114 and 116, respectively. The magnetic bias structure(s) 122, 123, and/or 124 may be soft bias structures fabricated with soft magnetic material(s). In other implementations, the magnetic bias structure(s) 122, 123, and/or 124 may be hard magnetic bias structures. Other mechanisms for biasing the sensors 112, 114 and 116 might also be used.

The read sensors are separated by shields 130 and 140. The read sensors 112, 114 and 116 and mid-shields 130 and 140 are surrounded by read shields 120 and 150. Thus, as used herein, a mid-shield shield may be considered to be an internal shield, which is interleaved with read sensors 112, 114 and 116 and between the outer, read shields 120, 150. The outermost shields 120, 150 for the read transducer 110 are termed read shields. In the implementation shown in FIGS. 2 and 3, three read sensors 112, 114 and 116 and two internal shields 130 and 140 are shown. However, in another implementation, another number of read sensors 112, 114 and 116 and internal shields 130 and 140 may be present. The shields/read shields 120, 130, 140 and 150 generally include soft magnetic material. In some implementations, one or more of the shields 120, 130, 140 and 150 may include ferromagnetic layers that are anti-ferromagnetically coupled.

Current is driven perpendicular-to-plane for the sensors 112, 114 and 116. Thus, current is driven through the sensor 112 between the shields 120 and 130. Similarly, current is driven through the sensor 114 between the shields 130 and 140. Current is also driven through the sensor 116 between the shields 140 and 150. Thus, electrical connection is to be made to the shields 120, 130, 140 and 150. However, different currents may be desired to be driven through the sensors 112, 114 and 116. Similarly, the resistances of the sensors 112, 114 and 116 may be desired to be separately sensed. For example, the sensors 112, 114 and 116 may each be desired to be separately coupled to their own preamplifier (preamp). As a result, the sensors 112, 114 and 116 are desired to be electrically isolated from each other. Consequently, the shields 130 and 140 are configured to not only magnetically shield the sensors 112, 114 and 116, but also to provide electrical isolation. As a result, each middle shield 130 and 140 may include multiple conductive magnetic layers separated by one or more insulating layers. Thus, the shield 130 may include conductive magnetic middle shield layers 134 and 136 that are separated by an insulating layer 152. In some embodiments, the insulating layer 152 may be considered a magnetic-spacer layer 152. Similarly, the shield 140 includes conductive magnetic middle shield layers 144 and 146 separated by a magnetic shield layer 162. However, example implementations are not limited to this configuration, and may include configurations without an insulating layer 152, 162 formed between the conductive magnetic middle shield layers 134/144, 136/146. Further, in some embodiments, the conductive magnetic layers 134/144/136/146 may be formed from a conductive metal and may be referred to as metallic middle shield layers.

The insulating layer(s) 152 and/or 162 may also be configured to improve the performance of the shields 130 and/or 140, respectively. For example, a low dielectric constant material may be used for the insulating layers 152 and/or 162. A low dielectric constant material is one which has a dielectric constant less than eight. For example, SiO and/or SiOC might be used for the insulating layer(s) 152 and/or 162. As a result, capacitive coupling between the metallic middle shield layers 134 and 136 and/or the metallic middle shield layers 144 and 146 may be reduced. The thickness of the insulating layer(s) 152 and/or 162 may be varied. More specifically, the thickness of the insulating layer(s) 152 and/or 162 may be increased distal from the sensors 112, 114, and 116. In some implementations, the insulating layer 152 and 162 may be on the order of ten nanometers within five microns of the sensors 112, 114 and 116. Further from the sensors 112, 114 and 116, the thickness may be increased, for example to twenty nanometers. In addition, the material(s) may be changed further from the sensors 112, 114 and 116. For example, the insulating layer 152 may include a ten nanometer thick alumina sub-layer having a dielectric constant of approximately six. At least five microns from the sensors an additional sub-layer of silicon dioxide having a thickness of approximately ten nanometers with a dielectric constant of approximately three may be added. Thus, the insulating layer(s) 152 and/or 162 may have varying thicknesses and/or materials.

Additionally, in each shield 130 and 140, an electrical contact layer is formed between each sensor 112,114,116 and respective middle shield layers 134,136,144,146. For example, electrical contact layer 132 is formed between sensor 112 and middle shield layer 134. Similarly, electrical contact layer 138 is formed between sensor 114 and middle shield layer 136. Additionally, electrical contact layer 142 is formed between sensor 114 and middle shield layer 144. Further, electrical contact layer 148 is formed between sensor 116 and middle shield layer 148. In the illustrated embodiments, the electrical contact layers 132, 138, 142, 148 are illustrated as separate layers. However, the electrical contact layers 132, 138, 142, 148 are not limited to this configuration, and may be formed as a portion of the respective adjacent middle shield layers 134, 136, 144, 146.

In some implementations, the electrical contact layer is formed form the same materials as the neighboring sensors 112,114,116 and may be formed during the formation of neighboring sensor as discussed in greater detailed below. For example, electrical contact layer 132 may be formed during formation of the sensor 112. Further, electrical contact layers 138 and 142 may be formed during formation of the sensor 114. Additionally, electrical contact layer 148 may be formed during formation of the sensor 116.

The read transducer 110 may be used in higher density recording, such as TDMR. Through the placement of the sensors 112, 114 and 116, the transducer 110 may address skew issues that might otherwise adversely affect performance of the transducer 110. Consequently, the impedance and response of the transducer 110 may be sufficient for higher frequency performance. Cross talk may thus be reduced. In addition, the effect on the magnetics and other aspects of the transducer 110 because of the reduced overlap may be mitigated by the configuration of the shields 130 and 140. Performance of the magnetic transducer 110 may thus be improved.

FIG. 4 is a plan view of the exemplary implementation of the microstructure 190 of the present application. The microstructure 190 includes the read transducer 110 and an interconnection region 200 that may be removed during manufacturing of the read transducer 110. Specifically, once all of the layers of the read transducer 110 have been formed, the interconnection region 200 may be removed along plane 180 via known manufacturing methods to form the Air Bearing Surface (ABS) of the read transducer. Of course, embodiments of the present application need not have the interconnection region 200 be removed during processing and manufacturing of the read transducer 110.

As illustrated, each of the electrical contact layers 132/142/138/148 extend from the read transducer 110 into the interconnection region 200. Further, a shunt region 172/174/177/179 may be formed on the portions of the electrical contact layers 132/142/138/148 that extend into the interconnection region 200.

As illustrated, the upper most electrical contact layer 148 extends furthest into the interconnection region 200 and has the shunt region 177 formed thereon. Additionally, the electrical contact layer 142 extends into the interconnection region 200 less than electrical contact layer 132 and has the shunt region 179 formed thereon. Further, the electrical contact layer 138 extends over the shunt region 179 and has shunt region 174 formed thereon. Further, the lower most electrical contact layer 132 extends least furthest into the interconnection region 200 and has the shunt region 172 formed thereon. The lower most electrical contact layer 132 is the electrical contact layer closest to the lower outer shield 120. As discussed in the above embodiments, the electrical contact layers 132, 138, 142, 148 are illustrated as separate layers. However, the electrical contact layers 132, 138, 142, 148 are not limited to this configuration, and may be formed as a portion of the respective adjacent middle shield layers 134, 136, 144, 146.

Further, an electrical connection 170 is formed between the shunt region 172 and the shunt region 174. Additionally, and electrical connection 175 is formed between the shunt region 177 and the shunt region 177. In some embodiments, the electrical connections 170 and 175 may be formed as an electrically conductive layer, which provides minimal resistance and shorts together the respective shunt regions. In other embodiments, the electrical connections 170 and 175 may be formed from an electrically resistive layer that provides a specific level of resistance. For example, each electrical connection 170, 175 may be formed from the same materials as the read sensors and may provide a defined resistance value. For example, each electrical connection 170/175 may have provided an electrical resistance substantially equal to 10 kw plus or minus normal manufacturing tolerances.

By providing shunt regions 172/174/177/179 with electrical connections 170/175 therebetween, Electrical Overstress (EOS) or Electrostatic Discharge (ESD) during manufacturing may be reduced. Further, by provided a defined resistance between the shunt regions 172/174/177/179, the electrical properties of read transducer 110 may be measured during manufacturing prior to completion.

Additionally, in some embodiments an electrical connection (not shown) may be provided between the outer read shields 120 and 150 in the interconnection region 200 to electrically short together the outer read shields 120 and 150. Such an electrical connection or short between the outer read shields 120 and 150 may provide additional protection against EOS and ESD.

FIGS. 5A and 5B illustrate an exemplary implementation of a method 500 for manufacturing the read transducer. For simplicity, some steps may be omitted, interleaved, and/or combined. The method 500 is also described in the context of providing a single recording transducer having two read sensors. However, the method 500 may be used to form a portion or a complete two-dimensional transducer, such as TDMR transducers 110 illustrated in FIGS. 2-3 and/or the microstructure 190 of FIG. 4. Further, the method 500 may also be used to fabricate multiple transducers at substantially the same time. The method 500 may also be used to fabricate other transducers, as may be apparent to a person of ordinary skill in the art. The method 500 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 500 also may start after formation of other portions of the magnetic recording transducer.

In 505, a first outer shield layer 120 is formed. The first outer shield layer 120 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the first outer shield layer 120 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

Further, in 510, a first read sensor 112 is formed on the first outer shield layer 120. As discussed above, each read sensor 112, 114, and 116 may include a pinning layer, a pinned layer, a nonmagnetic spacer layer, and a free layer 113, 115, and 117, respectively. The pinning layer is generally an AFM layer that is magnetically coupled to the pinned layer. In other implementations, however, the pinning layer may be omitted or may use a different pinning mechanism. The free layers 113, 115 and 117 are each shown as a single layer, but may include multiple layers including but not limited to a synthetic antiferromagnetic (SAF) structure. The pinned layer may also be a simple layer or a multilayer. Although shown as extending the same distance from the ABS, the pinned layer may extend further than the corresponding free layer 113, 115, and/or 117, respectively. Further, the formation process of the first read sensor 112 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

After the first read sensor 112 is formed, a first electrical contact layer 132 may be formed over the first read sensor 112 in 515. The first electrical contact layer 132 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the first electrical contact layer 132 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

The first electrical contact layer 132 is formed to extend into the interconnection region 200 illustrated in FIG. 4. Further during the formation of the first electrical contact layer 132, the shunt region 172 is also formed using the same materials as the electrical contact layer. In some embodiments, the formation of the first electrical contact layer 132 may formed during the formation of the read sensor 112 and in some embodiments the formation of the first electrical contact layer 132 may be a separate, discrete process from the sensor 112 formation.

In 520, a first metallic middle-shield layer 134 is formed over the first electrical contact layer 132. The first metallic middle-shield layer 134 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the first metallic middle-shield layer 134 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

As discussed above, the first electrical contact layer 132 is illustrated as a separate layer. However, the first electrical contact layers 132 is not limited to this configuration, and may be formed as a portion of the adjacent first metallic middle-shield layer 134.

In 525, a second metallic middle-shield layer 136 is formed above the first metallic middle-shield layer 134. In some implementations, the insulation layer 152 may be formed between the first and second metallic middle-shield layers 134, 136. The second metallic middle-shield layer 136 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the second metallic middle-shield layer 136 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

In 530, a second electrical contact layer 138 may be formed over the second middle-shield layer 136. The second electrical contact layer 138 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the second electrical contact layer 138 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

The second electrical contact layer 138 is formed to extend into the interconnection region 200 illustrated in FIG. 4. Further during the formation of the second electrical contact layer 138, the shunt region 174 is also formed using the same materials as the electrical contact layer. Additionally the electrical connection 175 may also be formed during the formation of the second electrical contact layer 138.

As discussed above, the second electrical contact layer 138 is illustrated as a separate layer. However, the second electrical contact layers 138 is not limited to this configuration, and may be formed as a portion of the adjacent second metallic middle-shield layer 136.

Further, in 535, a second read sensor 114 is formed above the second middle-shield shield layer 136. In some embodiments, the second electrical contact layer 138 may formed during the formation of the second read sensor 114 in 535 and in some embodiments the formation of the second electrical contact layer 138 may be a separate, discrete process from the sensor 114 formation.

As discussed above, each read sensor 112, 114, and 116 may include a pinning layer, a pinned layer, a nonmagnetic spacer layer, and a free layer 113, 115, and 117, respectively. The pinning layer is generally an AFM layer that is magnetically coupled to the pinned layer. In other implementations, however, the pinning layer may be omitted or may use a different pinning mechanism. The free layers 113, 115 and 117 are each shown as a single layer, but may include multiple layers including but not limited to a synthetic antiferromagnetic (SAF) structure. The pinned layer may also be a simple layer or a multilayer. Although shown as extending the same distance from the ABS, the pinned layer may extend further than the corresponding free layer 113, 115, and/or 117, respectively. Further, the formation process of the second read sensor 114 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

After the second read sensor 114 is formed, a third electrical contact layer 142 may be formed over the second read sensor 114 in 540. The third electrical contact layer 142 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the third electrical contact layer 142 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

The third electrical contact layer 142 is formed to extend into the interconnection region 200 illustrated in FIG. 4. Further during the formation of the third electrical contact layer 142, the shunt region 179 is also formed using the same materials as the electrical contact layer. In some embodiments, the formation of the third electrical contact layer 142 may formed during the formation of the read sensor 114 and in some embodiments the formation of the third electrical contact layer 142 may be a separate, discrete process from the sensor 114 formation.

In 545, a third metallic middle-shield layer 144 is formed over the third electrical contact layer 142. The third metallic middle-shield layer 144 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the third metallic middle-shield layer 144 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

As discussed above, the third electrical contact layer 142 is illustrated as a separate layer. However, the third electrical contact layers 142 is not limited to this configuration, and may be formed as a portion of the adjacent third metallic middle-shield layer 144.

In 550, a fourth metallic middle-shield layer 146 is formed above the third metallic middle-shield layer 144. In some implementations, the insulation layer 162 may be formed between the third and fourth metallic middle-shield layers 144, 146. The fourth metallic middle-shield layer 146 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the fourth metallic middle-shield layer 146 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

In 555, a fourth electrical contact layer 148 may be formed over the fourth middle-shield layer 146. The fourth electrical contact layer 148 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the fourth electrical contact layer 148 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

The fourth electrical contact layer 148 is formed to extend into the interconnection region 200 illustrated in FIG. 4. Further during the formation of the fourth electrical contact layer 148, the shunt region 177 is also formed using the same materials as the electrical contact layer. Additionally the electrical connection 170 may also be formed during the formation of the second electrical contact layer 148.

As discussed above, the fourth electrical contact layer 148 is illustrated as a separate layer. However, the fourth electrical contact layers 148 is not limited to this configuration, and may be formed as a portion of the adjacent fourth metallic middle-shield layer 146.

Further, in 560, a third read sensor 116 is formed above the fourth middle-shield shield layer 146. In some embodiments, the fourth electrical contact layer 148 may formed during the formation of the third read sensor 114 in 560 and in some embodiments the formation of the fourth electrical contact layer 148 may be a separate, discrete process from the sensor 116 formation.

As discussed above, each read sensor 112, 114, and 116 may include a pinning layer, a pinned layer, a nonmagnetic spacer layer, and a free layer 113, 115, and 117, respectively. The pinning layer is generally an AFM layer that is magnetically coupled to the pinned layer. In other implementations, however, the pinning layer may be omitted or may use a different pinning mechanism. The free layers 113, 115 and 117 are each shown as a single layer, but may include multiple layers including but not limited to a synthetic antiferromagnetic (SAF) structure. The pinned layer may also be a simple layer or a multilayer. Although shown as extending the same distance from the ABS, the pinned layer may extend further than the corresponding free layer 113, 115, and/or 117, respectively. Further, the formation process of the third read sensor 116 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process.

In 565, a second outer shield layer 150 is formed over the third read sensor 116. The second outer shield layer 150 may generally be formed from a soft-magnetic material including, but not limited to, Iron alloys, Nickel alloys, or any other soft-magnetic metal that may be apparent to a person of ordinary skill in the art. Further, the application process of the second outer shield layer 150 is not particularly limited and may include any process that may be apparent to a person of ordinary skill in the art including sputtering or any other known process. Once the second outer shield layer 150 is formed in 565 the process 500 may end in some implementations. However, in some implementations, the interconnection region 200 may be removed along plane 180 to form the ABS. The removal of the interconnection region 200 may be done through any process that may be apparent to a person of ordinary skill in the art (such as dicing, etching, etc.).

The foregoing detailed description has set forth various implementations of the devices and/or processes via the use of block diagrams, schematics, and examples. Insofar as such block diagrams, schematics, and examples contain one or more functions and/or operations, each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof.

While certain implementations have been described, these implementations have been presented by way of example only, and are not intended to limit the scope of the protection. Indeed, the novel methods and apparatuses described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the protection. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the protection. 

What is claimed is:
 1. A method of making a magnetic head, the method comprising: forming a first read sensor and a first electrical contact formed with a first shunt region; forming a first mid-shield layer on the first read sensor, the first mid-shield layer being electrically connected to the first electrical contact; forming a second mid-shield layer over the first mid-shield layer; and forming a second read sensor over the second mid-shield layer, the second read sensor having a second electrical contact formed with a second shunt region electrically connected to the first shunt region.
 2. The method of claim 1, wherein the forming the first read sensor comprises: forming a read sensor area of the read sensor; and forming the first electrical contact after the first read sensor has been formed.
 3. The method of claim 1, wherein forming the second electrical contact electrically connected to the second mid-shield layer comprises forming an electrically resistive layer between the first shunt region and the second shunt region.
 4. The method of claim 3, wherein the electrically resistive layer is formed to have an electrical resistance substantially equal to 10 kw.
 5. The method of claim 1, wherein the forming the first read sensor comprises: forming a first outer shield layer; and forming the first read sensor over the first outer shield layer; and wherein the method further comprises: forming a second outer shield layer over the second read sensor.
 6. The method of claim 1, wherein the forming the first electrical contact comprises forming the first shunt region in a region of the magnetic head to be removed during formation of an air bearing surface; wherein the forming the second electrical contact comprises forming the second shunt region in the region of the magnetic head to be removed during formation of the air bearing surface; and further comprising forming the air bearing surface by removing the first shunt region, and the second shunt region.
 7. The method of claim 1, wherein forming the second read sensor further comprises for forming a third electrical contact formed with a third shunt region, and wherein the method further comprising: forming a third mid-shield layer on the second read sensor, the third mid-shield layer being electrically connected to the third electrical contact; forming a fourth mid-shield layer over the third mid-shield layer; and forming a third read sensor over the fourth mid-shield layer, the third read sensor having a fourth electrical contact formed with a fourth shunt region electrically connected to the third shunt region.
 8. The method of claim 7, wherein forming the second electrical contact electrically connected to the second mid-shield layer comprises forming a first electrically resistive layer between the first shunt region and the second shunt region; and wherein forming the fourth electrical contact electrically connected to the fourth mid-shield layer comprises forming a second electrically resistive layer between the third shunt region and the fourth shunt region.
 9. The method of claim 7, wherein the forming the first read sensor comprises: forming a first outer shield layer; and forming the first read sensor over the first outer shield layer; and wherein the method further comprises: forming a second outer shield layer over the third read sensor.
 10. The method of claim 7, wherein the forming the first electrical contact comprises forming the first shunt region in a region of the magnetic head to be removed during formation of an air bearing surface; wherein the forming the second electrical contact comprises forming the second shunt region in the region of the magnetic head to be removed during formation of the air bearing surface; wherein the forming the third electrical contact comprises forming the third shunt region in a region of the magnetic head to be removed during formation of the air bearing surface; wherein the forming the fourth electrical contact comprises forming the fourth shunt region in the region of the magnetic head to be removed during formation of an air bearing surface; and further comprising forming the air bearing surface by removing the first shunt region, the second shunt region, the third shunt region, and the fourth shunt region.
 11. A method of assembling a storage drive comprising: forming a magnetic head using the method of claim 1; mounting the magnetic head on a slider arm; and mounting the slider arm proximate to a storage medium. 